Aqueous terpolymer sized nylon yarns



Alva F. Harris, Wilbraham,

Chemical Company, Delaware Mass, assignor to Monsanto St. Louis, Mo., a corporation of No Drawing. Application December 15, 1954 Serial No. 475,579

4 Claims. (Cl. 117139.5)

This invention relates to sized nylon yarns. More particularly, the invention relates to a new sizing composition for nylon yarns of the hexamethylene adipamide type and to the yarns sized therewith.

The advent of nylon yarns has presented many problems to textile manufacturers in finding a composition which can be used as an efiicient sizing material. Due to the chemical and physical properties of nylon yarns, the usual materials used as sizes for natural yarns such as cotton and wool yarns and the synthetic yarns such as viscose and acetate rayon yarns are not effective on the nylon yarns.

Many materials have been suggested for sizing nylon yarns and some have shown considerable promise. Among the better prior materials are copolymers of vinyl acetate and maleic anhydride and the partial alkyl half esters thereof. However, these materials are partially lacking in adhesion to the nylon, in stiffness and in abrasion resistance. They may be used and are being used for lack of a better material.

One object of this invention is to provide sized nylon yarns.

A further object of this invention is to provide a new sizing composition for nylon yarns.

Another object is to provide a process for sizing nylon yarns.

These and other objects are attained by preparing a terpolymer of vinyl acetate, maleic anhydride and styrene and sizing nylon yarns from an aqueous solution of the terpolymer.

The following examples are given in illustration and are not intended as limitations on the scope of this invention. Where parts are mentioned, they are parts by Weight.

Example I Prepare a copolymer of 49.5 mol percent of vinyl acetate, 48.5 mol percent of maleic anhydride and 2 mol percent of styrene by mass polymerization in the presence of a free radical catalyst and an agent for controlling the polymerization rate using such temperature conditions and amounts of additives to obtain a terpolymer having a viscosity of about 12 centipoises in a 5% aqueous solution at 25 C.

Dissolve 8 parts of the terpolymer in 92 parts of water and heat the solution to about 140 F. Draw nylon (polyhexamethylene adipamide) warp yarns having 70 filaments, a denier of 34 and 7 Z twist through the solution at a rate of 10 to 20 yards per minute and then pass the wet yarn between squeeze rolls adjusted to apply a pressure of 10 to 20 pounds per linear inch on the yarn. Then pass the yarn over five drying cans arranged in tandem and heated respectively to the following temperatures: 180 F., 200 F., 200 F., 200 F., and 160 F. After leaving the drying cans, the sized yarn is substantially dry. No sticking of the yarns or the size on the heated cans occurs. The nylon yarn thus treated has about 5% by weight of a flexible, tough and abrasion-resistant sizing of States Patent 2,848,357 Patented Aug. 19, 1958 prepared therefrom are stiffer and more abrasion resistant than similar fabrics prepared with a terpolymer of vinyl acetate, maleic anhydride and methyl acid maleate.

Example II Prepare a terpolymer similar to that of Example I except alter the conditions and amount of adjuvants to obtain a product having a viscosity of about 35 centipoises in a 5% solution at 25 C. As in Example I, size nylon yarns with an aqueous solution of this terpolymer, said solution containing 6 parts of terpolymer and 94 parts of water. Fabrics prepared from nylon yarns so treated have a sizing thereon of about 4% by weight of the terpolymer and have properties of stiffness and abrasion re sistance equivalent to the sized fabrics of Example I.

The sizing compositions of this invention are terpolymers of vinyl acetate, maleic anhydride and styrene or substituted styrenes. The ratio of vinyl acetate to maleic anhydride on a mol percent basis may range from 52:48 to 50:50. The amount of styrene or substituted styrene should be restricted to from 1.8 to 4 mol percent of the terpolymer. The styrene derivatives that may be used are alpha alkyl styrenes containing from 1 to 4 carbon atoms in the alkyl group, alpha chlorostyrene, ring-substituted monoand di-alkyl styrenes in which the alkyl groups contain from 1 to 4 carbon atoms, dialkyl styrenes in which the alkyl group is in the alpha position, and ringsubstituted monoand dichlorostyrenes.

The terpolymers should be prepared by mass polymerization in the presence of free radical producing catalysts and polymerization regulators under conditions carefully controlled to yield a product having a viscosity of 5 to centipoises measured in a 5% aqueous solution at 25 C. Such terpolymers are sufiiciently soluble in water to pro vide a sizing solution of the required solids content which should range from 2 to 15% .by weight.

The size solution may contain, in addition to the terpolymer, small amounts ranging from 0.01 to 25% by weight of sizing adjuncts such as humectants, oils, wetting agents and the like. As examples of humectants may be mentioned glycerin, ethylene glycol, sorbitol, propylene glycol, polyethylene glycols, polyglycerols, polypropylene oxides, etc. Oils which may be used include the sulfonated animal, mineral and vegetable oils or mixtures thereof, water-emulsifiable mixtures of such oils with animal oils, mineral oils, vegetable oils, Twitchell oil and the like. As examples of wetting agents may be mentioned acid-stable anionic wetting agents such as alkyl substituted benzene sodium sulfonates, in which the alkyl group contains from about 10 to 20 carbon atoms, alkali metal or ammonium monoalkyl sulfosuccinates, in which the alkyl group contains from about 10 to 20 carbon atoms, and the like; and acid-stable non-ionic wetting agents such as the surface active condensation products of ethylene oxide with an alkylated phenol having from 8 to 20 carbon atoms in the alkyl group or an alkyl mercaptan having from 8 to 20 carbon atoms.

For best results, the size solution should be used or applied to the nylon yarn at a temperature between about and 200 F. At these temperatures, the size solution is less viscous and penetrates into the yarn more readily and uniformly.

The size solution is supplied to the yarn in an amount sufiicient to apply between about 0.5 to 10% by weight of the terpolyrner based on the dry weight of the nylon yarn. This may be accomplished in various ways, for example, by passing the yarns through the size solution and beneath the surface thereof or by spraying the yarns with the size solution and thereafter passing the yarns between squeeze rolls to remove excess solution and to deposit the required amount of the terpolymer. The size solution may also be applied in other ways, as for example, by dipping the yarns in the solution of the terpolymer. In any event, the solution should contain between 2 and by weight of the terpolymer and, if squeeze rolls are used, the amount of pressure exerted on the squeeze rolls should be adjusted to remove sufficient excess solution to deposit the required amount of terpolymer within the range of 0.5 and 10%, based on the weight of the dry yarn.

The treated nylon yarns may be dried in various ways. Thus, they may be air-dried at normal room temperatures, that is, between about 65 and 85 F. However, it is preferred to dry the treated yarns at elevated temperatures of about 140 to 250 F. This may be accomplished by passing the treated yarns through an oven in which the circulating air is at a temperature of 140 to 250 F. or the treated yarns may be passed over one or more drying cans, which are heated at a temperature of 140 to 250 F., until the yarns are dry or contain less than 10% moisture.

The sized yarns are now ready for the weaving operation and may be woven in a loom at a relative humidity between about 40 and 80%. Any suitable yarn may be used as the filling in the weaving operation. The size adheres to the nylon yarns during the weaving operation without splitting or dusting oif and protects the yarns from the mechanically moving parts of the loom. This excellent adhesion of the size of the nylon yarns is particularly unexpected in view of the fact that alkali metal salts of the same terpolymers lack adhesion'to nylon yarns during the weaving operation, and especially when it is considered that nylon yarns undergo considerable stretching and contraction in the loom and thus subject the size to considerable stretching and contraction. The terpolyrner sizes disclosed herein are also sufficiently hard so that they dry on drying cans without sticking to the cans.

The size, which consists essentially of the terpolymers hereinbefore described, is readily removed from the warp yarns in the Woven fabric by a simple scouring or soaping in a mild soap solution. This means that the fabric can be treated with any suitable finishing agent to produce the desired finish on the fabric.

The term nylon as used herein is intended to include water-insoluble fiber-forming linear polyamides, particularly the water-insoluble fiber-forming linear polyamides prepared by condensing an aliphatic diamine such as hexamethylene diamine with an aliphatic polybasic acid such as adipic acid or sebacic acid, such as the polyamides described in United States Patents No. 2,071,250, No.

2,130,532 and No. 2,130,948. Of the foregoing linear polyamides, it is preferred to size the water-insoluble, polyhexamethylene-adipamide warp yarns, since they are commercially available and are especially amenable to sizing by the methods of this invention.

What is claimed is:

1. A method of sizing water-insoluble nylon warp yarns to prepare them for weaving which comprises treating said yarns with an aqueous solution comprising from about 2 to 15% by weight of a terpolymer of vinyl acetate, maleic anhydride and a styrene compound taken from the group consisting of styrene, alpha alkyl styrenes, alpha chlorostyrene, ring-substituted mono and di-alkyl and chlorostyrenes, and dialkyl styrenes in which one alkyl group is in the alpha position, said alkyl groups containing from 1 to 4 carbon atoms, the mol percent ratio of vinyl acetate to maleic anhydride varying from 52:48 to 50:50 and the mol percent ratio of styrene compound ranging from 1.8 to 4 in the terpolymer, said solution being supplied in an amount sufficient to deposit from about 0.5 to 10% by weight, based on the dry-yarns, of said terpolymer, and then drying said yarns.

2. A nylon warp yarn bearing, based on the dry yarn, 0.5 to 10% by weight of a flexible and tough size of a water-soluble terpolymer of vinyl acetate, maleic anhydride and a styrene compound taken from the group consisting of styrene, alpha alkyl styrenes, alpha chlorostyrene, ring-substituted monoand di-alkyl and chlorostyrenes, dialkyl styrenes in which one alkyl group is in the alpha position, and mixtures thereof, said alkyl groups containing from 1 to 4 carbon atoms, the mol percent ratio of vinyl acetate to maleic anhydride varying from 52:48 to 50:50 and the mol percent ratio of styrene compound ranging from 1.8 to 4 in the terpolymer.

3. A nylon Warp yarn as in claim 2 wherein the styrene compound is styrene.

4. A nylon warp yarn hearing about 5% by weight of the yarn of a flexible tough size of a water-soluble terrnol percent of vinyl acetate, 48.5 mol percent of maleic anhydride and 2 mol percent of styrene.

References Cited in the file of this patent UNITED STATES PATENTS 2,047,398 Voss July 14, 1936 2,469,407 Powers May 10, 1949 2,469,409 Powers May 10, 1949 2,519,764 Jacobson Aug. 22, 1950 2,576,915 Barrett Dec. 4, 1951 2,609,350 Spatt Sept. 2, 1952 2,616,867 Rossin Nov. 4, 1952 2,675,370 Barrett Apr. 13, 1954 

1. A METHOD OF SIZING WATER-INSOLUBLE NYLON WARM YARNS TO PREPARE THEM FOR WEAVING WHICH COMPRISES TREATING SAID YARNS WITH AN AQUEOUS SOLUTION COMPRISING FROM ABOUT 2 TO 15% BY WEIGHT OF A TERPOLYMER OF VINYL ACETATE, MALEIC ANHYDRIDE AND A STYRENE COMPOUND TAKEN FROM THE GROUP CONSISTING OF STYRENE, ALPHA ALKYL STYRENES, ALPHA CHLOROSTYRENE, RING-SUBSTITUTED MONO- AND DI-ALKYL AND CHLOROSTYRENES, AND DIALKYL STYRENES IN WHICH ONE ALKYL GROUPS IS IN THE ALPHA POSITION, SAID ALKYL GROUPS CONTAINING FROM 1 TO 4 CARBON ATOMS, THE MOL PERCENT RATIO OF VINYL ACETATE TO MALEIC ANHYDRIDE VARYING FROM 52:48 TO 50:50 AND THE MOL PRECENT RATIO OF STYRENE COMPOUND RANGING FROM 1.8 TO 4 IN THE TERPOLYMER, SAID SOLUTION BEING SUPPLIED IN AN AMOUNT SUFFICIENT TO DEPOSIT FROM ABOUT 0.5 TO 10% BY WEIGHT, BASED ON THE DRY YARNS, OF SAID TERPOLYMER, AND THEN DRYING SAID YARNS. 